54 



the buccal cavity (pharynx?), which also becomes visible in other Lum- 

 bricidae. Beddard l ) and Benham s ) too take to the view, that ,the 

 prostomium is absent and that the mouth opens terminally." 



I cannot quite agree with this opinion. Although in the most of our 

 specimens the cephalic extremity is inverted — the first segment with 

 bristles thus lying foremost — such is not the case with all of them. 



The examination of a longitudinal section of such a specimen (PI. Til, 

 fig. 33) proves, that a lobe of the buccal segment extends dorsally 

 beyond the mouth. Such a lobe was also observed in an other indi- 

 vidual, (PI. IV, fig. 35) and shows at its ventral side a pair of longitu- 

 dinal grooves, which diverge towards the anterior extremity. In 

 transverse sections too these grooves were visible; they show no 

 particular structure, but their epithelial layer is not so high as in 

 the surrounding. 



I believe , that the figure of a longitudinal section of the anterior 

 end of P. corethrurus (Quart. Journ. Micr. So. Vol. XXIX, PI. XXIII, 

 fig. 1) published by Beddard, is too diagrammatical, and does not 

 represent a sagittal but a tangential section. Moreover another mistake 

 has been made into this figure , as already indicated by Rosa , viz. that 

 the pore of the mucous gland is figured in the third segment , furnished 

 with bristles, instead of in the first. As the tubes of these mucous 

 glands in their structure much resemble those of the nephridia, and 

 moreover the latter organs are absent in segment II en III, Perrier 

 already made the suggestion, that the mucous gland would represent a 

 highly developed nephridium; Beddard now believes to have demon- 

 strated the perfect homology of both organs , by finding out the internal 

 funnels of the mucous gland. For he observed „three or four funnels 

 of considerable size and of a somewhat horse- shoeshaped form; two 

 of them were situated at the distal extremity of the gland in the 

 sixth (fourth? Bedd.) segment, the third more anterior in position, 

 corresponding to the fifth." I quite agree with Rosa, that the 

 exactness of this observation is not without doubt , for Beddard says : 

 „the mucous glands occupy the first six segments, which contain no 

 nephridia of the normal type ; these latter do not commence until after." 

 This must be a slip of the pen , for as visible in fig. 34 , nephridia are 



1) Quartl. Journ. Micr. Sc. vol. XX KI, 1890, p. 159; Proc. R. Phys. Soc. Edinburgh, 

 1891, p. 235. 



2) Quartl. Journ. Microsc. Sc. XXXI, p. 250. 



